No doubt this will descend into the usual bunfight but I'll be honest, here goes...
If you were the OW and the 'man' left his wife / got kicked out and you're now with him, are you happy?
He left her (they had no kids), she is 10 years younger than him, I am his age and have three children (I say this to show that I'm not the younger childfree woman people typically think OWs are). We are together and we are very happy.
Is living with him how you thought it would be when you were sneaking around having covert liaisons?
We don't live together, yet (partly we're taking it slowly because of my children). I didn't have a set view of how it would be to be able to spend more time together, I just wanted to have the opportunity to find out what it would be like to have a 'normal' relationship. After he left we started 'dating', it wasn't a foregone conclusion that we would have an ongoing relationship.
And knowing he's capable of lying and cheating to someone he loves how do you ever trust him?
This will sound harsh but he didn't love her. He cared for her after being together for over 20 years (he still does). They had become friends not lovers.
I trust him because we communicate - neither of us did this well in our previous relationships. We've learned from our mistakes and are open and honest with each other including about things that are difficult to talk about (of which there have been many).
We both acknowledge that if we'd done this in our previous relationships then maybe things would've been different. But we didn't and they weren't.
We are different people now and are determined not to make the same mistakes.